Invasion History

First Non-native North American Tidal Record: 1989
First Non-native West Coast Tidal Record: 1989
First Non-native East/Gulf Coast Tidal Record:

General Invasion History:

Laonome cf. calida was described from the Calliope River, Queensland, Australia (Capa 2007). In Australia, it has been found in open-water marine environments in the Dampier Archipelago, Western Australia, but also in brackish estuaries, with little or no tide, near Darwin (Northern Territory), and in Queensland (Capa 2007; Capa et al. 2014). In 1989, an unidentified sabellid was found in large numbers in the Sacramento-San Joaquin Delta, and originally identified as Potamilla sp. Similar poychaetes were found in 2009 in fresh and brackish canals in the Netherlands, and identified as Laonome cf. calida (Capa et al. 2014). The San Francisco estuary population also appears to fit the description of L. cf. calida (Leslie Harris, personal communication, 3/27/15). One surprising aspect of these invasions, assuming that these populations are all L. cf. calida, is the successful adaptation of a tropical animal to a temperate habitat. Genetic studies of these populations would be useful for testing variation in species traits and identifications.

North American Invasion History:

Invasion History on the West Coast:

Laonome cf. calida, initially identified as Potamilla sp. was first collected in 1989 in Sherman Lake in the western Sacramento-San Joaquin Delta (Cohen and Carlton 1995). It has reached very high densities (up to 16000 m-2) at the confluence of the San Joaquin and Sacramento Rivers, and has been found from inner tributaries of the Delta (Franks Tract, Old Rover) to San Pablo Bay (Cohen and Carlton 1995; Barnett et al. 2007). It was abundant at salinities of ~8 PSU and most abundant in wet years at a lower Sacramento River station, but during dry years it was most abundant at a freshwater station (Old River) (Peterson and Vayssieres 2010). It may be transported in ship fouling or ballast water (Hsieh et al. 2010) aboard commercial vessels. It has been found in fouling communities of retired ships moored in Suisun Bay (Llanso et al. 2011). On the West Coast, L. cf. calida has only been found in the San Francisco estuary.

Invasion History Elsewhere in the World:

In 2009-2012, an unidentified sabellid was found to be abundant at many sites in brackish and fresh canals and rivers in the Rhine, Meuse and Scheldt deltas of the Netherlands. These worms were found to fit the morphological characters of L. cf. calida (Capa 2007; Capa et al. 2014). They were found at salinities of 0 – 4.5 PSU, in silt and clay in canals, on stones, in fresh intertidal mudflats, and non-tidal freshwater riparian mudflats. The populations apparently survived winter water temperatures of 0-5°C (Capa et al. 2014).

In 2012, a population of sabellids of the genus Laonome was discovered in Parnu Bay, Estonia, on the Gulf of Riga, at a salinity of 3-5 PSU. These polychaetes appear to be a different, undescribed, and introduced species of Laonome (Kotta et al. 2015).


Laonome cf. calida is a sabellid polychaete described from Queensland, Australia (Capa 2007). Populations of introduced sabellids in low-salinity waters of the San Francisco Bay estuary and brackish-to-fresh canals and rivers of the Netherlands show minor differences from Australian specimens (Capa et al. 2014; Leslie Harris, personal communication 2015). Further morphological and genetic studies will be needed to confirm the conspecific status of these populations. Another introduced population, in Parnu Bay, Estonia, on the Baltic Sea, appears to be a distinct, unidentified species (Kotta et al. 2015). Recent sutides indicate that all of the European specimens, from the Baltic and Azov Seas, and the Netherlands, are a distinct new species. Laonome xeprovala, disitnct from L. calida. sp. nov. (Bick et al. 2018).

Sabellid polychaetes are often called 'feather-duster worms' and are characterized by having a prostomium with the palps modified into a crown of feather-like radioles. The peristomium is modified into an anterior collar, into which the radioles can be withdrawn. The body has a short thoracic region (6-8 chaetigers) and a longer abdominal region, of a few-to-many chaetigers. A ciliated ventral groove runs from the ventral anus along the ventral side of the abdomen and then swings to the dorsal side of the thorax, continuing as a divide in the peristomial collar (Blake and Ruff 2007).

Laonome cf. calida has a branchial crown of 7 radioles on each of the two lobes, comprising about 1/3 of the body length. The body is cylindrical, tapering posteriorly, with 6-8 thoracic chaetigers and 14-31 abdominal chaetigers. The radioles form semicircles on the two lobes of the crown. The radioles lack eyespots, but are marked with 4-8 pigmented bands. The radioles lack lateral flanges at their bases, but are supported internally by 2 rows of vacuolated cells. The anterior edge of the collar is even in height, while the posterior edge of the collar forms two sub-triangular ventral lobes. The mid-ventral incision cuts through about half the length of the collar. The dorsal lips, on each side of the fecal groove, are rounded, and the lateral margins are smooth. 

The first thoracic chaetiger of Laonome cf. calida is separated from the collar by a fine groove, and bears two rows of narrow, hooded chaetae. The subsequent thoracic chaetigers have two rows of chaetae as well, an upper row with elongate, narrowly hooded chaetae, and a lower row of paleate (scale-like) chaetae. The thoracic chaetigers also bear rows of uncinae, short, deeply embedded chaetae, with one large tooth and several fine ones, and lacking a handle at the base. The abdominal chaetigers have broadly hooded neurochaetae and the unicini have 5 rows of 2-4 teeth above the main fang. The posterior 10-15 chaetigers are increasingly narrow, and may have a mid-ventral depression. The pygidium is conical, with a mid-ventral groove. Australian specimens were 10-29 mm long, while European worms were 9-15 mm (Capa 2007; Capa et al. 2014). The tube consists of a thin layer of mucus, with fine particles attached. Description based on: Norris 2006, Capa 2007, Barnett et al. 2011, and Capa et al. 2014. Laonome xeprovala differs from L. calida in having fewer thoracic chaetigers (fewer than 45, compared to ~87 in one L. c. specimen. Bick et al. 2018).


Taxonomic Tree

Kingdom:   Animalia
Phylum:   Annelida
Class:   Polychaeta
Subclass:   Palpata
Order:   Canalipalpata
Suborder:   Sabellida
Family:   Sabellidae
Genus:   Laonome
Species:   cf. calida


Potamilla sp. (Cohen and Carlton, 1995)

Potentially Misidentified Species

Laonome kroyeri
Laonome kroyeri Malmgren, 1866 has a broad circumpolar distribution (Appeltans et al. 2017)



There is limited reported information on the ecology of this species. A related species, L. albicingillum, from estuarine habitats in Taiwan, is hermaphroditic, undergoes self-fertilization and has lecithotrophic, weakly-swimming, planktonic larvae. Larvae take 25-33 hours from fertilization to settlement (Hsieh 1995a; Hsieh 1995b; Hiseh et al. 2010).


Phytoplankton, detritus

Trophic Status:

Suspension Feeder



General HabitatUnstructured BottomNone
General HabitatVessel HullNone
General HabitatRockyNone
Salinity RangeOligohaline0.5-5 PSU
Salinity RangeMesohaline5-18 PSU
Salinity RangeLimnetic0-0.5 PSU
Tidal RangeSubtidalNone
Vertical HabitatEndobenthicNone
Vertical HabitatEpibenthicNone

Tolerances and Life History Parameters

Minimum Salinity (‰)0.1Field, Old River, San Joaquin Delta, Peterson and Vayssieres 2010
Maximum Salinity (‰)35Open marine sites, Dampier Archipelago (Capa et al. 2007).
Maximum Length (mm)15Capa et al. 2011
Broad Temperature RangeNoneCold temperate-Tropical
Broad Salinity RangeNoneLimnetic-Mesohaline

General Impacts

Laonome calida is a significant suspension feeder, responisble for ~7% of estimated phytoplankton grazing in Suisun Slough, in the Sacramento-San Joaquin Delta (Jones et al. 2009).

Regional Impacts

NEP-VNorthern California to Mid Channel IslandsEcological ImpactHabitat Change
Mucus from the tubes of Laonome sp as well as the mucus produced by other native and introduced deposit feeding and tube-building benthos, contributes to a surface layer of flocculent fluff, which may trap much more phtyoplankton than that actually consumed by the animals (Jones et al. 2009).
P090San Francisco BayEcological ImpactHabitat Change
Mucus from the tubes of Laonome sp. as well as the mucus produced by other native and introduced deposit feeding and tube-building benthos, contributes to a surface layer of flocculent fluff, which may trap much more phtyoplankton than that actually consumed by the animals (Jones et al. 2009).
CACaliforniaEcological ImpactHabitat Change
Mucus from the tubes of Laonome sp as well as the mucus produced by other native and introduced deposit feeding and tube-building benthos, contributes to a surface layer of flocculent fluff, which may trap much more phtyoplankton than that actually consumed by the animals (Jones et al. 2009)., Mucus from the tubes of Laonome sp. as well as the mucus produced by other native and introduced deposit feeding and tube-building benthos, contributes to a surface layer of flocculent fluff, which may trap much more phtyoplankton than that actually consumed by the animals (Jones et al. 2009).

Regional Distribution Map

Bioregion Region Name Year Invasion Status Population Status
NEP-V Northern California to Mid Channel Islands 1989 Def Estab
P090 San Francisco Bay 1989 Def Estab
AUS-II None 0 Native Estab
AUS-I None 0 Native Estab
AUS-XII None 0 Native Estab
NEA-II None 2009 Def Estab
B-VIII None 2014 Def Estab
B-X None 2015 Def Estab
MED-X None 2013 Def Estab
B-III None 2018 Def Estab
B-VI None 2018 Def Estab

Occurrence Map

OCC_ID Author Year Date Locality Status Latitude Longitude


Appeltans, W. et al. 2011-2015 World Registry of Marine Species. <missing URL>

Associated Press (12/2021) Lummi Nation declares disaster after invasive crab arrives, Seattle Times <missing volume>: <missing location>

Barbosa, Andreia C. C. Vinagre, Catarina Mizrahi, Damián Flores, Augusto A. V. (2019) Temperature-driven secondary competence windows may increase the dispersal potential of invasive sun corals, Marine Biology 166: Published online

Barnett, Rachel; Bell, Sabrina; Floerke, Wyatt; Templin, Bill (2011) <missing title>, California Interagency Ecological Program, Sacramento CA. Pp. 13

Bick, Andreas (2005) A new Spionidae (Polychaeta) from North Carolina, and a redescription of Marenzelleria wireni Augener, 1913, from Spitsbergen, with a key for all species of Marenzelleria., Helgoland Marine Research 59: 265-272

Blake, James A.; Ruff, R. Eugene (2007) The Light and Smith Manual: Intertidal invertebrates from Central California to Oregon (4th edition), University of California, Berkeley CA. Pp. 309-410

Capa, Maria (2007) Taxonomic revision and phylogenetic relationships of apomorphic sabellids (Polychaeta) from Australia, Invertebrate Systematics 21: 537-567

Capa, María; van Moorsel, Godfried; Tempelman, David (2014) The Australian feather-duster worm Laonome calida Capa, 2007 (Annelida: Sabellidae) introduced into European inland waters?, Bioinvasions Records 3: in press

Carlton, James T. (Ed.) (2007) The Light and Smith Manual: Intertidal Invertebrates from Central California to Oregon Fourth Edition, Completely Revised and Expanded, University of California Press, Berkeley. Pp. <missing location>

Cohen, Andrew N.; Carlton, James T. (1995) Nonindigenous aquatic species in a United States estuary: a case study of the biological invasions of the San Francisco Bay and Delta, U.S. Fish and Wildlife Service and National Sea Grant College Program (Connecticut Sea Grant), Washington DC, Silver Spring MD.. Pp. <missing location>

Delgado, Lídia; Guerao, Guillermo; Ribera, Carles (2009) The Gammaridea (Amphipoda) fauna in a Mediterranean coastal lagoon: Considerations on population structure and reproductive biology, Crustaceana 82(2): 191-218

Hsieh, Hwey-Lian (1995) Laonome albicingillum, a new fan worm species (Polychaeta:Sabellidae:Sabellinae) from Taiwan, Proceedings of the Biological Society of Washington 108(1): 130-135

Hsieh, Hwey-Lian (1997) Self-fertilization: a potential fertilization mode in an estuarine sabellid polychaete, Marine Ecology Progress Series 147: 143-148

Hsieh, Hwey-Lian; Fan, Lan-Feng; Po-Chen, Chang; Wu, Jiunn-Tzong; Liu, Wen-Cheng (2010) Effects of semidiurnal tidal circulation on the distribution of holo- and meroplankton in a subtropical estuary, Journal of Plankton Research 32(6): 829-841

Jones, Nicole L.; Thompson, Janet K.; Arrigo, Kevin R.; Monismith, Stephen G. (2009) Hydrodynamic control of phytoplankton loss to the benthos in an estuarine environment, Limnology and Oceanography 54(3): 952-969

Kotta, Jonne; Kotta, Ilmar; Bick, Andreas; Bastrop, Ralf; Väinölä, Risto (2015) Modelling habitat range and seasonality of a new, non-indigenous polychaete Laonome sp. (Sabellida, Sabellidae) in Pärnu Bay, the north-eastern Baltic Sea, Aquatic icology 10(3): 275-285

Llansó, Roberto J.; Sillett, Kristine; Scott, Lisa (2011) <missing title>, Versar, Inc., Columbia MD. Pp. <missing location>

Norris, D. (2006) <missing title>, City and County of San Francisco, San Francisco. Pp. 1-2

Peterson, Heather A.; Vayssieres, Marc (2010) Benthic assemblage variability in the upper San Francisco estuary: A 27-year retrospective, San Francisco Estuary and Watershed Science <missing volume>: published online

Teaca, Adrian; Begun, Tatiana; Menabit,Selma; Muresan,Mihaela (2022) The First Record of Marenzelleria neglecta and the Spread of Laonome xeprovala in the Danube Delta–Black Sea Ecosystem, Diversity 14(423): Published line